Researchers discover vanishing lakes, lost continents and radioactive rocks that may explain a rhode island sized iceberg.
Antarctica should be the subject of more attention in the mainstream media as it the single largest body of ice on our planet and one of the greatest preliminary indicators of climate change. Wherever you stand in that debate, if you care deeply enough about the truth you should be keeping an eye out for whats going on at our southernmost continent.
Scientists previously expected that there were a bunch of large subglacial lakes beneath the ice sheets of East Antarctica. After discovering a series of undulating ice pockets on the surface of Recovery Glacier they concluded that some sort of subglacial tide must be forcing the ice up and down by several meters. According to previous observations it would all seem to check out.
“The vertical motion has always been attributed, and in some other places proven, to be associated with water bodies beneath the ice,” Scambos told Live Science.
However, that is not what they found.
Back in 2014 the research team conducted a fly over radar scan of the area and must’ve not fully understood the data until relatively recently as it appears that most of these oscillatory ice pockets do not have lakes beneath them, which begs the question – what is causing the ice to go up and down?
“There have been four really large lakes suggested and 11 smaller lakes, and we found by far less,” said the study leader, glaciologist Angelika Humbert of the Alfred Wegener Institute’s Helmholtz Center for Polar and Marine Research in Germany
Recovery Glacier is a basin 621 miles (1,000 kilometers) long that drains 8 percent of East Antarcticas volumetric mass in to the ocean.
“They’re probably not there,” Humbert said.
Their findings were published in the Journal of Geophysical Research
One possibility is that their scan was conducted at a time where most of the water was submerged underground. We now know for example that there is much more water inside the Earth then previously assumed. In fact the planets is basically “breathing” water in and out of the ocean, making climatological models more difficult to approximate.
Is it possible that there is some kind of subterranean cave system beneath Antarctica cycling water in and out of openings near the bedrock?
An old satellite has been resurrected from the dead to better understand the effect of gravity on continental drift, particularly towards our southernmost continent, Antarctica where it is otherwise difficult to obtain data.
The Gravity field and Ocean Circulation Explorer (GOCE), a European Space Agency (ESA) satellite operated from 2009 to 2013. From re-inspecting the satellites data scientists gleaned more insight into the phenomena of continental drift, and the underlying landmass of Antarctica in comparison to other continents.
During it’s operation the GOCE satellite studied the effects of gravity on oceans and landmass based on factors such as latitude (you weigh about 0.5% more at the poles than on the equator) and differences in planetary density beneath the surface. With this information you can create a time-map of continental drift.
All of this was compiled in to a video animation that depicts Antarcticas journey from Pangaea to it’s current location at our south pole.
“These gravity images are revolutionizing our ability to study the least understood continent on Earth—Antarctica,” said study co-author Fausto Ferraccioli, science leader of geology and Geophysics at the British Antarctic Survey, in a statement.
“Cratons” are an upwelling of landmass centerfold on shifting tectonic plates – basically another word for continent. During continental drift ‘cratons’ rise and fall beneath the ocean. Using data from GOCE scientists were able to spot several ancient cratons beneath the surface of East Antarctica. Which means that there is certainly a significant amount of landmass beneath the ice. However West Antarctica in particular, lacks any massive cratons due to a smaller lithosphere according to the researchers.
“The comparisons demonstrate that the combination of seismological, and satellite gravity gradient imaging has significant potential to enhance our knowledge of Earth’s structure,” the study concluded.
The journal was published in Scientific Reports,
For some reason Antarctica is melting from the bottom-up as well. Ever since scientists discovered signs of what they expect to be a massive mantle plume of hot rock beneath the surface of East Antarctica, they have been trying to find out more about these “geothermal anomalies”. Especially since a Rhode Island sized iceberg broke off the continent.
The British Antarctic Survey (BAS) in particular was studying streams of ice-water that begin inside of East Antarctica and end up draining into the ocean. The BAS team used radar scans to pierce through 1.8 miles of ice, measuring thickness and revealing the sub-glacial basins beneath.
According to their journal, published in Scientific Reports, the team discovered an area with an unusually large amount of geothermal activity. So much so that it was melting the ice above and causing it to sag down. They’ve proposed an explanation called “radiogenic granitoids”— which are basically radioactive minerals that heat up water from inside of the Earth and cause it to expand, squeezing out of the mantle. In the case of East Antarctica once certain barriers melt away the warm subterranean water can flood subglacial lakes downstream – perhaps providing us with an explanation for the ice pocket anomalies discussed earlier in th3 article.
“The process of melting we observe has probably been going on for thousands or maybe even millions of years and isn’t directly contributing to ice sheet change,” Tom Jordan from the BAS and lead author of the study, said in a statement.
If there is any resemblance of cyclical predictability to the subterranean reservoir-like pumping of water from inside the Earth, understanding it would be vital to more accurately distinguishing man-made from natural climate change.
“This was a really exciting project, exploring one of the last totally unsurveyed regions on our planet. Our results were quite unexpected, as many people thought this region of Antarctica was made of ancient and cold rocks, which had little impact on the ice sheet above. We show that even in the ancient continental interior, the underlying geology can have a significant impact on the ice.”